1. Field of the Invention
This invention relates to a liquid crystal display, and more particularly to a lamp apparatus for a liquid crystal display that prevents wire breakage within the lamp apparatus.
2. Description of the Related Art
Generally, a liquid crystal display (LCD) is widely used as a display device in notebook personal computers or portable televisions. LCDs typically include an upper substrate, a lower substrate, a liquid crystal display panel with a liquid crystal layer provided between the upper substrate and the lower substrate, and a back light installed at the lower side of the lower substrate to provide the liquid crystal display panel with an uniform surface light source.
The LCD requires a back light unit because it is not a self-emitting display device. The back light unit includes a lamp apparatus that generates light as shown in FIG. 1.
Referring to FIG. 1, a conventional lamp apparatus for the LCD includes a lamp 2, a wire 3 for supplying the lamp 2 with power, solder 4 for electrically contacting the lamp with the wire 3, a shrinking tube 10 for enclosing the wire 3 and the solder 4, and a lamp holder 5 for enclosing an end of the lamp 2 and the solder 4.
The lamp 2 receives driving power from a power source (not shown) to generate light. Driving power is fed to the lamp 2 by way of the wire 3. To this end, the wire 3 and the lamp 2 are electrically connected to each other by a soldering method using a lead.
The shrinking tube 10 is manually provided to enclose the wire 3, the solder 4, and the end of the lamp 2 to carry out a voltage-resistance test and to prevent wire breakage within the lamp apparatus. The lamp holder 5 encloses the tube 10 and the end of the lamp 2 so as to protect the soldering portion 4 from an external impact. The lamp holder 5 is made from a material such as soft rubber.
Referring to FIGS. 2A-2D, an assembly method of the abovementioned conventional lamp apparatus for the LCD will now be described. As shown in FIG. 2A, a lead forming a solder pad 12 is electrically contacted to the lamp 2 and the solder 4 is placed on the solder pad to form a solder bump. Referring to FIGS. 2B and 2C, a wire electrode 13 is formed to electrically contact the wire 3 and, upon heating the solder 4, is pressed into the solder 4 such that the lamp 2 is in electrical communication with the wire 3. Subsequently, the shrinking tube 10 is formed to enclose the wire 3 and the solder 4. The lamp holder 5 is then fitted over the end of the wire 3 and the edge of the lamp 2 as shown in FIG. 3. The lamp holder 5 allows the lamp 2, the solder 4 and the wire 3 to be integrated.
The LCD lamp apparatus formed using the conventional soldering method is then subjected to a wire breakage test: During the breakage test, the wire 3 is shaken about 50 to 60 times in the left and right directions repeatedly as indicated in the bilateral arrow ‘B’ in FIG. 3. An external force according to such a breakage test is transferred into the end portion ‘A’ of the wire 3 and the solder 4 to break the wire 3. The wire 3 breaks because the lamp holder 5, which encloses the lamp 2, the solder 4, and the wire 3, is not completely attached to the lamp 2, the solder 4, and the wire 3.
Wire breakage is a problem because driving power cannot be fed to the lamp 2. Hence, the lamp 2 cannot be turned on. Another problem arises because the solder 4, the shrinking tube 10, and the lamp holder 5 must be assembled manually. It has been found that manual assembly produces low yields in the fabrication process.